I have been a Utah state certified safety inspector for 18 years and have extensive experience diagnosing and repairing brake systems on different vehicles. For this case, it appears the truck that was pulling the trailer was equipped with disc brakes. Thus, it was equipped with pads and rotors. If the trailer that it was pulling was equipped with electrically operated trailer brakes, then improper harnessing or incorrectly connected wiring between the truck and the trailer could cause the trailer brakes to operate improperly or not at all. That would put an extra burden on the truck brake system because it must slow and stop not only the truck and its load but also the trailer and its load. This could possibly lead to the necessity of having to replace brake hardware and parts more often. However, there may also be a problem in the truck braking system, causing the need for more frequent maintenance and subsequent repairs.